A base station antenna designed for broadband mobile communications networks may include one or more arrays, each array comprising a plurality of radiating antenna elements, and the arrays being capable of supporting one or multiple spectrum bands. The antenna elements of each array are connected to a radio frequency (RF) beamforming network (also referred to as a RF distribution network or a RF feed network), which is designed to distribute RF power to the antenna elements, when considering a signal for transmission via the array. The antenna elements of the array are typically arranged in a vertical plane and designed to create a relatively narrow radiation pattern beam in the elevation plane (of between 5 and 15 degrees, for example). Phase shifters may also be used between the RF feed network and the antenna elements. The phase shifters are used to impart a linearly varying phase slope along the antenna array and hence vary the boresight direction of the radiated pattern in the elevation plane. This is known as variable electrical tilt (VET) in order to control and optimize the cellular network coverage and interference parameters.
Mobile telecommunications operators deploy base station equipment which may include a baseband apparatus, radio equipment, and antennas. The radio equipment has been traditionally designed to provide RF signals for only one RF band, which in turn is connected to one or more radiating arrays of the base station antenna. For multiple RF bands at a base station site, multiple radios are connected to correspondingly multiple antennas. Each radio plus antenna combination may have the capability to vary the antenna beam tilt associated with the RF band connected to the antenna, for network design optimization purposes.